Calendar mechanism for time-pieces

ABSTRACT

In a calendar mechanism of the type in which the length of the month is taken into account making correction at the end of the months unnecessary, a new device is provided comprising a date disc and means for the advance of this date disc by a main lever having at one end an advance and lock mechanism for said date disc, said device comprising further a month cam engaged by the main lever such that the same shifts the date disc according to the length of the month. Such device is improved so as to be simple and compact in structure and to occupy substantially minimized space in time piece.

nite States Patet ni Eumier Oct. 15, 1974 4] CALENDAR MECHANISM FOR 3,373,558 3/l968 Makiri 58 58 x 3,673,789 7/l972 Tsuzuki ct al. 58/58 TIME PIECES '4 716983 2/!97? T l\ t l 58/5 an'a'ue a. t [75] inventor: Cyril Vuill Eumier, Bienne,

switzgrland FOREIGN PATENTS OR APPLICATIONS [73] Assigneez S0ciete Suisse pour L,ln ustr e 1,575,397 6/1969 France 58/58 ggggg g gzgsgsg Servlces Primary Examiner-George H. Miller, Jr.

Attorney, Agent, or Firm-Imirie and Smiley [22] Filed: Apr. 4, 1973 211 Appl. No.: 347,623 ABSTRACT In a calendar mechanism of the type in which the [30] Foreign Application Priority Data length of the month is taken into account making cor- A 5 1972 S l d 4947/72 rection at the end of the months unnecessary. a new Zer device is provided comprising a date disc and means for the advance of this date disc by a main lever havmg at one end an advance and lock mechanism for Fie'ld 58/4 5 58 said date disc, said device comprising further a month 7 cam engaged by the main lever such that the same shifts the date disc according to the length of the [56] References Clted month. Such device is improved so as to be simple and UNITED STATES PATENTS compact in structure and to occupy substantially mini- 2,286,000 6/1942 Neyhart 58/5 mized space in time piece. 2,483,775 10/1949 Klaris 2,709,885 6/1955 Van Kampen 58/5 8 Clam, 1 Drawmg Flgure CALENDAR MECHANISM FOR TIME-PIECES BACKGROUND OF THE INVENTION This invention relates generally to calendar mechanisms and more particularly to calendar mechanisms of the type in which the date indication or date disc is visible through an opening in the dial and the changing occurs by instantaneous steps, said mechanism comprising a date disc and means for the advance of the date disc, wherein said date disc revolves by a predetermined number of steps one time in 24 hours.

Mechanisms of this kind take the length of the month into account and make any manual corrections at the end of the 28 or 30 days-months unnecessary.

However, prior calendar mechanisms have many disadvantages. Particularly they are very complex in structure, large in size, and it is difficult to use them in small timepieces.

SUMMARY OF THE INVENTION Accordingly, an object of this invention is to provide a calendar mechanism of the described type which is compact and of which the dimensions allow its use in small timepieces. A calendar mechanism according to this invention comprises a main lever having at one end an advancing-and locking-device for the date disc, said lever having further a cam surface engaging a gudgeon or pin one time every 24 hours, said gudgeon being controlled by the clockwork to set and then to release said main lever, a part of said main lever leaning on a month cam which determines the displacement of said main lever. according to the length of the months, and advancing means controlled by said date disc, being provided for shifting the cam month at the end of every month. In a particular embodiment of this invention, the month cam is locked by a gear.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features and advantages of this invention will become apparent from the following description of an illustrative embodiment shown in the accompanying drawing by a single FIG- URE.

DESCRIPTION OF THE INVENTION A main lever 32 is rotatably mounted on a fixed shaft 61 and has a beak 33 leaning on the circumference of a month cam 34 which determines its displacement in a manner which will be described hereafter. The main lever 32 has at its end 35 a pinion 36 with ten teeth, which pinion is fixed on a plate 37 supporting two gudgeons on pins 38 and 39 adapted to engage the teeth or the date disc 40.

The month cam 34 is resiliently mounted on a toothed wheel 41 having 48 teeth. This wheel 41 is driven by a pinion 42 having teeth and mounted on a star 43 having ten branches 44.

A second cam 45 making a revolution in 24 hours controls a second lever 47 having a toothed segment 46 which is in engagement with the pinion 36 of the main lever 32.

A toothed wheel 48 is concentrically mounted above the hours-wheel (not shown) with which it rotates clockwise and shifts, by the gudgeon 49, the main lever 32 every 24 hours and releases it at midnight: it causes the instantaneous displacement of the date disc 40.

Two springs are provided acting on levers 32 and 47, namely a spring 50 acts on lever 32 and a spring 51 acts on lever 47.

The working mode of this mechanism will now be described:

The toothed wheel 48 mounted above the not-shown hourswheel makes one clockwise revolution in twentyfour hours. The gudgeon 49 fixed on this wheel 48 comes into contact with the main lever about six hours before midnight to rotate it clockwise about pivot 61 thereby lifting beak 33 away from cam by a slight distance. At midnight, the gudgeon 49 releases the main lever 32 which is pushed by the spring 50 and shifts the ,date disc 40 by the gudgeons 38 and 39. It is noted that the main lever 32 is a single assembly from its beak 33 to the end 35, but the beak 33 is not in the same plane as the end 35; it is offset upwardly as indicated in the drawing by a broken and a continuous line around the shaft 61. During this shifting, the toothed segment 46 of the lever 47 is disengaged from the pinion 36 of the main lever 32; consequently, this pinion 36 does not rotate and, thus, causes disc 40 to be shifted in a counterclockwise direction. The displacement of the main lever 32 and consequently the shifting of the date disc 40 are limited by the month cam 34, because the beak 33 of the main lever 32 butts against the periphery of cam 34.

After midnight, the toothed segment 46 engages the pinion 36 of the main lever 32 under control of cam 45 acting onto the lever 47. Consequently, while the main lever 32 returns'to its initial position, the pinion 36 and the plate 37 having the gudgeons 38 and 39 rotate withoutdisplacing the date disc 40 thus preventing any undesired displacements.

The cam 34 makes one revolution in one year. Therefore, it is driven periodically at the end of every month between the 28th and the 31st day by rotation through 4/48 of a revolution, by four pins 52, 53, 54 and 55 placed under the date disc 40. On the month cam 34, each month is represented by a sector 56 which is subdivided into four parts one for each 1/48 revolution caused by a corresponding one of the four pins. During the 28 first days of the month, the beak 33 of the main lever 32 butts against the peripheral first quarter 57 of a sector 56; at the 29th day, the beak 33 butts against the second quarter 58, at the 30th day, against the third quarter 59, and at the 31st day against the fourth quarter 60 because the pins 52 to 55 rotate the month cam during this four days each by a step of l/48 revolution. For the 30 days-months, the fourth quarters 60 of the sector 56 (corresponding to the months Apr., June, Sept. and Nov.) are smaller in diameter in order to allow to the main lever to give the date disc 40 a displacement corresponding to 2 days. The second, third and fourth quarters 58, 59 and 60 of the sector 56 corresponding to February are so small in diameter that the main lever 32 gives to the date disc 40 a displacement corresponding to four days the mechanism being illustrated in the position assumed immediately following the shifting of the date from Feb. 28 to Mar. 1.

It is necessary that the month cam 34 be. resiliently mounted on the toothed wheel 41 because the rotation of the month cam 34 and the penetration of the beak 33 of the main lever 32 into this month cam 34 occur at the same time, in order that the beak 33 be able to disengage from the notches of the month cam 34 and that this cam be able to rotate; This resilient coupling can be realized with a ring or an axis of plastic material.

In order to avoid any damages of the calendarmechanism when a correction of the time-indication is effected shortly after midnight, the gudgeon 49 is retractably mounted on the toothed wheel 48 to allow its sliping under the main lever 32. This can be realized with known means, for example with a spring.

Although a preferred embodiment has been described in detail with reference to the accompanying drawing, it is to be understood that the invention is not limited to the details shown and described, and that various changes and modifications can be made.

What is claimed is:

l. A calendar mechanism for timepieces with date indication through an opening in the dial and changing by instantaneous stepping, said mechanism comprising a date disc and advancing means for shifting said date disc by a predetermined number of steps once every 24 hours, said advancing means including a main lever having at one end thereof an advancing and locking mechanism for cooperation with said date disc and further having a cam surface, a gudgeon responsive to a dial train of the time-piece for coaction with said cam surface once every 24 hours to set and then to release said main lever, a month cam, a part of said main lever cooperating with said month cam during release thereof from said gudgeon for determining the displacement of said date disc by said main lever according to the length of the month, and advancing means controlled by said date disc for advancing said month cam at the end of every month.

2. Mechanism as claimed in claim 1, wherein said month cam is locked by a gear.

3. Mechanism as claimed in claim 1, wherein said advancing and locking mechanism of said date disc comprises a pinion and a plate.

4. Mechanism as claimed in claim 1, wherein said month cam has notches of different depths.

5. Mechanism as claimed in claim 1, wherein said date disc is in contact with said advancing and locking mechanism.

6. Mechanism as claimed in claim 1, wherein the gudgeon for the shifting of said main lever is retractably mounted on a wheel which is coaxially mounted above the hours-wheel, said wheel making a single revolution in 24 hours.

7. Mechanism as claimed in claim 1, wherein said date disc has four pins for advancing said month cam.

8. Mechanism as claimed in claim 7, comprising a star-like gear having ten branches, said gear being adapted to be engaged by said pins of the date disc for driving said month cam.

ap UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 8A1 08 4 Dated October 15, 197

Inventor(x) Cyril Vuilleumier It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Inventor's name should be: Cyril Vuilleumier Not: Cyril Vuill Eumier Signed and sealed this 14th day of January 1975.

(SEAL) Attest:

McCOY M'. GIBSON JR. c." MARSHALL DANN Attesting Officer Comissionerof Patents ORM go-150 069) USCOMM-DC 60376-P69 u.s. GOVERNMENT PRINTING omcz; 930

I UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. J" .3,8 ll,O8 t Dated October 15, 97

l vent fl Cyril Vuilleumier It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Inventor's name should be: Cyril Vuilleumier Not: Cy ril Vuill Eumier (SEAL) Attest:

McCOY M. GIBSON JR. Attesting Officer 0." MARSHALL DANN Commissioner of Patents USCOMM-DC 60376-P69 lLS GOVERNMNT PRINTING OFFICE: a 9 930 F ORM PO-l 050 (10-69) 

1. A calendar mechanism for timepieces with date indication through an opening in the dial and changing by instantaneous stepping, said mechanism comprising a date disc and advancing means for shifting said date disc by a predetermined number of steps once every 24 hours, said advancing means including a main lever having at one end thereof an advancing and locking mechanism for cooperation with said date disc and further having a cam surface, a gudgeon responsive to a dial train of the timepiece for coaction with said cam surface once every 24 hours to set and then to release said main lever, a month cam, a part of said main lever cooperating with said month cam during release thereof from said gudgeon for determining the displacement of said date disc by said main lever according to the length of the month, and advancing means controlled by said date disc for advancing said month cam at the end of every month.
 2. Mechanism as claimed in claim 1, wherein said month cam is locked by a gear.
 3. Mechanism as claimed in claim 1, wherein said advancing and locking mechanism of said date disc comprises a pinion and a plate.
 4. Mechanism as claimed in claim 1, wherein said month cam has notches of different depths.
 5. Mechanism as claimed in claim 1, wherein said date disc is in contact with said advancing and locking mechanism.
 6. Mechanism as claimed in claim 1, wherein the gudgeon for the shifting of said main lever is retractably mounted on a wheel which is coaxially mounted above the hours-wheel, said wheel making a single revolution in 24 hours.
 7. Mechanism as claimed in claim 1, wherein said date disc has four pins for advancing said month cam.
 8. Mechanism as claimed in claim 7, comprising a star-like gear having ten branches, said gear being adapted to be engaged by said pins of the date disc for driving said month cam. 